AUTOGRAPHIC TELEGRAPHY.

Globe, Volume XX, Issue 1611, 19 April 1879, Page 4

AUTOGRAPHIC TELEGRAPHY.

Autographic telegraphy, or the process of transmitting messages in the actual handwriting of the sender (says the “Times”), has occasionally during the past thirty years constituted the special study of scientific minds. So long since as 1850 Mr F. 0. Eakewell invented a copying telegraph by means of which autographic telegraphy was effected, and this was probably the first time it was effectually accomplished. In this instance the message was written by the sender with a gummy ink or varnish on metallic paper or tinfoil, and this writing was by the aid of mechanism used to actuate electric currents in such a way as to produce a record at the distant station by the chemical decomposition of a solution with which the receiving paper was damped. Both the written message and the paper were fixed round cylinders of similar form and dimensions, one being placed in the transmitting and the other in the recording instrument, and the cylinders were caused to revolve with corresponding velocities. Each time the gummy and, consequently, raised lines of the writing were crossed by a pointer under which the metallic paper was traversed in the transmitter, a mark corresponding in position was made on the prepared paper at the receiving end. It therefore followed that the sum of all the marks reproduced the writing itself. Mr Bakowell successfully reproduced the writing in white on a blue ground, but the process failed to become one of public utility, owing to the extreme slowness with which the apparatus worked and the difficulty that was experienced in maintaining uniform and synchronous motion in the instruments. In 1850, the Abbe Caselli, in Italy, endeavoured to solve the problem of autographic telegraphy in a similar manner. His apparatus was exhibited in England, and it was used practically between Paris and Marseilles, and Paris and Lyons. Plans, drawings and

autograph sketches were faithfully reproduced at distant places, but it was found that the apparatus had not only the defects of Bakewell’s, but it was very costly and complicated. Two other subsequent workers in this direction were M. Moyer and M. Lenoir, who tried to accomplish the same results with ordinary ink. _ They however pursued their investigations quite independently of and unknown to each other. We have recently been afforded the opportunity of examining the latest example of this class of apparatus at the General Post Office, where it has been submitted to the authorities for trial. This is the invention of M. d’Arlincourt, of Paris, and its general principles are similar to those which govern Bakewoll’s system. The distinguishing feature in d’Arlincourt’s apparatus, however, is the introduction of an extremely ingenious synchronous movement, by means of which the speed or travel of the cylinders is rendered uniform, both in the transmitting and the recording machine. The message to be sent, which may bo cither in the ordinary shorthand, is written with a thick gummy ink upon a strip of metallic-faced paper about 12in. long and 2£in. deep, which is wrapped around the cylinder of the transmitting instrument. A strip of white paper, chemically prepared and of similar dimensions, is placed on the cylinder of the recording apparatus, and the instruments are placed in electrical connection and started. The raised writing, actuating the electric current, causes a reproduction of the original message in fac-simile on the paper in the recording instrument, which may be hundreds of miles away from the other. Upon the occasion of our visit the two instruments, although in the same room, were practically placed 200 miles apart. The writing can be reproduced in either blue, brown, rod, or black, according to the chemical preparation of the paper, but always on a white ground, and a number of copies can be taken from one original. In the same way, sketches, plans, or drawings may be faithfully transmitted ; some sketches were, in fact, accurately reproduced on the occasion of our visit. Although the apparatus is perfect in its action, it still has one drawback which was common to its predecessors —that of slowness of reproduction. The time occupied in revolving the cylinder a sufficient number of times to allow the pointer to traverse the whole surface of of the paper is seven minutes, and this rate of speed is far below that required and attained in practice for commercial purposes. The Post-office authorities, to whom we are indebted for our inspection, do not, therefore, see their way to utilise M. d’Arlincourt’s ingenious invention at present. It is, however, being worked in Prance in fortresses and for similar military purposes, for use in which, and in some special cases, it is exceedingly well adapted.